Resistor



June 28, 1938. H R 2,122,160

RES ISTOR Filed Odt 26, 19:55

IN V EN TOR.

A TTORNEYS.

Patented June 28, 1938 UNITED STATES RESISTOR Harold C. Sherk, Erie,Pa., assignor to Eric Resistor Corporation, Erie, Pa., a corporation ofPennsylvania Application October 26, 1933, Serial No. 695,362

10 Claims.

The present invention is designed to provide a resistor of a formparticularly advantageous in avoiding disturbances caused by sparkcircuits of automobiles in which it is desired to install a radio. Inthe present invention the resistor is so formed that it may be readilyattached to the ordinary standard spark plug. With such resistors it isdesirable to include a resistor element of sufiicient length and crosssection to assure efficient and uniform operation and at the same timeform a structure occupying small space and fully protected from outsidecontacts. It is also preferable to form the resistor so that it may beattached on the spark plug as close to the gap as possible in order tohave as little conductor surface between the gap and the resistor aspossible. In the present invention a comparatively long resistor elementis provided with a convenient and small space and the structure as awhole is completely protected from outside disturbance. Features anddetails of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in theaccompanying drawing as follows:

Fig. 1 shows an elevation of a spark plug with the resistor in placethereon.

Fig. 2 an enlarged view, partly in section, of the resistor.

Fig. 3 a section on the line 33 in Fig. 2.

Fig. 4 a section on the line 44 in Fig. 3.

Fig. 5 a plan view of the resistor element.

I marks a spark plug. This may be of any standard form ordinarily havingan upper screwthreaded terminal 2 with the usual spark gap la.

The resistor has a sleeve 3 which is adapted to be screwed on to theupper end 2 of the spark plug. This sleeve is provided with a shoulder 4and a nurled or roughened edge 5. An upper terminal B for the resistorhas a shoulder l which is provided with a nurled, or roughened edge 8and an extension 9 below the shoulder which is of the same diameter andconcentric with the sleeve 3.

An insulating ring 10 is arranged around the sleeve and in contact withthe shoulder 4. An insulating sleeve H is arranged around the sleeve 3and extension 9 and has a flange l2 the surface of which opposes thering It.

A resistor element 13, preferably of a molding composition, is in theform of a split ring. The ends of the split ring are plated withconductor material at H. Ordinarily this is provided by spraying acopper coating on the end of the ring.

A connector I5 is electrically connected with one conductor end M ofthesplit ring and the sleeve 3. A similar connector it is electricallyconnected with the connector end 54 on the opposite end of the ring andthis connector is electrically connected with the shoulder l of theterminal 6. Preferably an insulating separating piece I! is providedbetween the sleeve 3 and the end of the extension 9.

With the parts so far described in assembled position the parts areencased in a material, such as bakelite, and the assembly placed in amold and a case I8 is formed in the closing of the mold setting of thebakelite under heat and pressure. The case so formed entirely enclosesthe resistor parts and secures these parts in assembly. In order to moredefinitely secure the terminals the nurled, or roughened surfaces 5 and8 are provided which, as the bakelite, or encasing material is moldedand subjected to pressure flows into the indentures formed in the metalterminals and thus assures a union. The element in the form of the ringgives a desirable length of resistor element in a very small space. Theopening through the ring is utilized for the terminals and the wholeassembly has a cylindrical form with the axis of the terminals as acenter without obstructions and the bakelite completely insulates aswell as encloses the element and parts from any accidental contact fromwithout.

What I claim as new is:

1. In a resistor, the combination of a split ring of compositionresistor material; separated and oppositely axially extending terminalsfor the ring; insulation for the split ring; and electric connectionsbetween circumferentially spaced portions of the ring and the terminals,said con nections being within the axially projected area of the ring,

2. In a resistor, the combination of a split ring of compositionresistor material; separated and oppositely axially extending terminalsfor the ring concentric with the ring; insulation for the split ring;and electric connections between circumferentially spaced portions ofthe ring and the terminals, said connections being within the axiallyprojected area of the ring.

3. In a resistor, the combination of a split ring of compositionresistor material; separated and oppositely axially extending terminalsfor the ring, one of which is screw-threaded; insulation for the splitring; and electric connections between circumferentiallly spacedportions of the ring and the terminals, said connections being withinthe axially projected area of the ring.

4. In a resistor, the combination of a split ring of compositionresistor material; separated and oppositely axially extending terminalsfor the resistor; connections between the terminals andcircumferentially spaced portions of the ring; and means insulating andencasing the ring and connections comprising a case molded to theterminals and uniting the terminal and ring assembly, said terminals andconnections being within the axially projected area of the case.

5. In a resistor, the combination of a split ring of compositionresistor material; an insulating sleeve Within the ring; axiallydirected terminals extending into the sleeve; connections between theterminals and circumferentially spaced portions of the resistor ring;and a case secured to the terminals and enclosing the ring andconnections and securing the parts in assembly.

6. In a resistor, the combination of a split ring of compositionresistor material; an insulating sleeve within the ring; axiallydirected terminals extending into the sleeve; connections between theterminals and circumferentially spaced portions of the resistor ring;and a case molded to the terminals and enclosing the ring and securingthe parts in assembly.

7. In a resistor, the combination of a split ring of compositionresistor material; an insulating means comprising a sleeve within thering and extending portions over the face of the ring; axially directedterminals extending into the sleeve; and connections betweencircumferentially spaced portions of the ring and the terminals.

8. In a resistor, the combination of a split ring of compositionresistor material; an insulating means comprising a sleeve within thering and extending portions over the face of the ring; axially directedterminals extending into the sleeve; connections betweencircumferentially spaced portions of the ring and the terminals; and acase secured to the terminals enclosing the ring and securing theterminals, ring and in sulation in assembly.

9. In a resistor, the combination of a split ring of resistor material;an insulating means comprising a sleeve within the ring and extendingportions over the face of the ring; axially directed terminals extendinginto the sleeve, said terminals having shoulders extending over theinsulation at the ends of the sleeve; connections betweencircumferentially spaced portions of the ring and the terminals and acase secured to the terminals enclosing the ring and securing theterminals, ring and insulation in assembly.

10. A resistance device comprising a molded block of non-conductivematerial, a hollow internally threaded terminal member embedded in oneend of the block and having an open end, a second terminal member havingan enlarged portion embedded in the block at its opposite end andprovided with an integral threaded post projecting from the end of theblock, a split annular resistance element within the block intermediatethe embedded portions of the terminal members, and conductor elementsconnecting the ends of the split annular resistance element with theterminal members, said terminal members and resistance element beingaxially alined and said resistance and conductor elements being embeddedin said block of non-conductive material.

HAROLD C. SHERK.

